Morphometric study of the primary ossification center of the frontal squama in the human fetus

PURPOSES: Detailed morphometric data on the development of ossification centers in human fetuses is useful in the early detection of skeletal dysplasias associated with a delayed development of ossification centers and their mineralization. Quantitative analysis of primary ossification centers of cranial bones is sporadic due to limited availability of fetal material. MATERIAL AND METHODS: The size of the primary ossification center of the frontal squama in 37 human (16 males and 21 females) spontaneously aborted human fetuses aged 18–30 weeks was studied by means of CT, digital-image analysis and statistics. RESULTS: With neither sex nor laterality differences, the best-fit growth dynamics for the primary ossification center of the frontal squama was modelled by the following functions: y = 13.756 + 0.021 × (age)(2) ± 0.024 for its vertical diameter, y = 0.956 + 0.956 × age ± 0.823 for its transverse diameter, y = 38.285 + 0.889 × (age)(2) ± 0.034 for its projection surface area, and y = 90.020 + 1.375 × (age)(2) ± 11.441 for its volume. CONCLUSIONS: Our findings for the primary ossification center of the frontal squama may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the skull in human fetuses.